An inkjet image forming apparatus forming an image on a sheet by ejecting an ink supplied via a supplying port of a liquid storage as an ink drop from a recording head is widely known.
For example, in Patent Document 1, an ink cartridge, in which a liquid chamber storing an ink of a liquid is formed and an ink supplying port bored in a wall face of the liquid chamber is sealed by an elastic sealing material, is disclosed. This ink cartridge is slid on a carriage stand and connected to a printing head as a connected subject. At this time, a hollow needle arranged at a side of the printing head pierces the elastic sealing material of the ink supplying port of the ink cartridge to be inserted into the liquid chamber.